ISO 17804:2020

INTERNATIONAL ISO
STANDARD 17804
Second edition
2020-06
Founding — Ausferritic spheroidal
graphite cast irons — Classification
Fonderie — Fontes ausferritiques à graphite sphéroïdal —
Classification
Reference number
ISO 17804:2020(E)
©
ISO 2020

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ISO 17804:2020(E)

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© ISO 2020
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Published in Switzerland
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ISO 17804:2020(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Designation . 2
5 Order information . 3
6 Manufacture . 3
7 Requirements . 3
7.1 General . 3
7.2 Test pieces machined from cast samples . 3
7.2.1 General. 3
7.2.2 Impact test . 4
7.3 Test pieces machined from samples cut from a casting . 5
7.4 Hardness . 5
7.5 Graphite structure . 5
7.6 Matrix structure . 5
8 Sampling . 5
8.1 General . 5
8.2 Cast samples . 6
8.2.1 Size of cast samples . 6
8.2.2 Frequency and number of tests . 6
8.2.3 Separately cast samples . 7
8.2.4 Side-by-side cast samples . 9
8.2.5 Cast-on samples .10
8.2.6 Test pieces machined from cast samples .12
8.3 Samples cut from a casting .12
8.4 Formation of test units and number of tests .13
8.4.1 General.13
8.4.2 Examples of test units .13
8.4.3 Number of tests per test unit .13
9 Test methods .13
9.1 Tensile test .13
9.2 Impact test .14
9.3 Hardness test .14
9.4 Graphite structure examination .15
10 Retests .15
10.1 Need for retesting .15
10.2 Test validity .15
10.3 Nonconforming test results .15
10.4 Heat treatment of samples and castings .15
11 Additional information .16
Annex A (normative) Abrasion-resistant grades of ausferritic spheroidal graphite cast iron .17
Annex B (normative) Minimum elongation values for a test piece with original gauge length
L = 4 × d .19
o
Annex C (informative) Guidance values for Brinell hardness .21
Annex D (informative) Procedure for the determination of the hardness range .22
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ISO 17804:2020(E)

Annex E (informative) Guidance values for tensile strength and elongation after fracture
[ ]
for test pieces machined from samples cut from a casting 4 .24
Annex F (informative) Unnotched impact test .25
Annex G (informative) Additional information on mechanical and physical properties .27
Annex H (informative) Nodularity .31
Annex I (informative) Sectioning procedure for cast samples .32
Annex J (informative) Cross-references of similar grades of ausferritic spheroidal graphite
cast iron .33
Bibliography .34
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ISO 17804:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 25, Cast irons and pig irons.
This second edition cancels and replaces the first edition (ISO 17804:2005), which has been technically
revised. The main changes compared with the previous edition are as follows:
a) the normative references have been updated;
b) the terms and definitions have been improved and supplemented;
c) a side-by-side cast sample has been included;
d) the method of manufacturing has been made more detailed (including pouring/heat treatment);
e) a subclause (9.4) for graphite structure examination has been added;
f) in Annex C (formerly Annex B), a new conversion table for tensile test results has been added;
g) in Annex H (formerly Annex G), new fatigue data have been added for five different test methods
from an international survey;
h) in Annex I (formerly Annex H), nodularity has been made more detailed, in accordance with
[2]
ISO 945-4 ;
i) the previous Annex I on machinability has been deleted as it is no longer necessary;
j) in Annex J, Chinese GB/T grades have been added and several other international grade changes
have been made;
k) the Bibliography has been revised.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO 17804:2020(E)

Introduction
Ausferritic spheroidal graphite cast iron is a cast alloy, iron, carbon and silicon based, carbon primarily
in the form of spheroidal graphite particles.
[3]
Compared to the spheroidal graphite cast iron grades (see ISO 1083 ), four material grades combine
high strength, ductility and toughness properties while two grades combine higher strength with wear
resistance as a result of ausferrite matrix structures.
This document deals with the classification of ausferritic spheroidal graphite cast irons in accordance
with the mechanical properties of the material.
The mechanical properties of these ausferritic spheroidal graphite cast irons depend on their structure,
e.g. the form of the graphite and the structure of the matrix.
The required structure is developed by selecting the appropriate composition and subsequent
processing.
The mechanical properties of the material can be evaluated on machined test pieces prepared from:
— separately cast samples with an appropriate gating system, able to provide metallurgical conditions
similar to those of the castings they represent;
— samples cast in the mould alongside the casting, with a joint running system, hereafter called “side-
by-side cast samples”;
— samples cast onto either the casting or the running system, hereafter referred to as “cast-on
samples”;
— samples cut from a casting (only by agreement between the manufacturer and the purchaser, the
agreement specifying, in particular, the conditions of sampling and the values to be obtained).
Two grades of ausferritic spheroidal graphite cast iron are specified in Annex A, in accordance with
their hardness. These cast irons are used in applications where high abrasion resistance is required
(e.g. mining, earth moving and manufacturing industries).
Five grades of ausferritic spheroidal graphite cast iron are specified by their mechanical properties.
When, for these grades, hardness is a requirement for the application, Annex D provides the means for
determining appropriate hardness ranges.
Some ausferritic spheroidal graphite cast iron grades can be used for pressure equipment.
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INTERNATIONAL STANDARD ISO 17804:2020(E)
Founding — Ausferritic spheroidal graphite cast irons —
Classification
1 Scope
This document defines the grades and the corresponding requirements for ausferritic spheroidal
graphite cast irons.
This document specifies five grades of ausferritic spheroidal graphite cast iron by a classification based
on mechanical properties determined on machined test pieces prepared from:
— separately cast samples, side-by-side cast or cast-on samples;
— samples cut from a casting.
This document also specifies two grades by a classification as a function of hardness.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 945-1, Microstructure of cast irons — Part 1: Graphite classification by visual analysis
ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO/TR 15931, Designation system for cast irons and pig irons
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
ausferritic spheroidal graphite cast iron
austempered ductile iron
ADI
cast material, iron, carbon and silicon based, carbon being present mainly in the form of spheroidal
graphite particles, subjected to an austempering heat treatment in order to produce an ausferritic matrix
3.2
graphite spheroidizing treatment
process that brings the liquid iron into contact with a substance to produce graphite in the spheroidal
form (predominantly form VI) during solidification
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ISO 17804:2020(E)

3.3
austempering
heat treatment process, consisting of heating the castings to a
temperature at which austenite starts to form during heating and holding a sufficient time for carbon
diffusion into the austenite, followed by cooling at a rate sufficient to avoid the formation of pearlite,
and transforming the matrix structure for a time and a temperature (above the martensite start
temperature) sufficient to produce the desired properties
Note 1 to entry: This process produces a microstructure that consists predominantly of ferrite and high carbon
austenite. This microstructure is called “ausferrite”. Examples of ausferritic microstructures are given in
[1]
ISO/TR 945-3 .
3.4
ausferrite
cast iron microstructure, produced by a controlled thermal process, which consists of predominantly
acicular ferrite and high carbon austenite
3.5
cast sample
quantity of material cast to represent the cast material, including separately cast samples, side-by-side
cast samples and cast-on samples
3.6
separately cast sample
sample cast in a separate sand mould under representative manufacturing conditions and material grade
3.7
side-by-side cast sample
sample cast in the mould alongside the casting, with a joint running system
3.8
cast-on sample
sample attached directly to the casting
3.9
relevant wall thickness
section of the casting, agreed between the manufacturer and the purchaser, to which the determined
mechanical properties apply
Note 1 to entry: Relevant wall thickness may be associated with a range of casting sections and/or with a
sample type and size according to Table 3. The association is made by considering the cooling conditions during
solidification and heat treatment.
3.10
test unit
inspection lot
test batch
number of pieces or the tonnage of castings to be accepted or rejected together, on the basis of the
tests carried out on the test pieces in accordance with the requirements of the relevant specification,
material standard or order
4 Designation
The material shall be designated in accordance with ISO/TR 15931.
Annex J gives a selection of approximate cross-references of grade designations from this document to
standard grades from EN, ASTM, JIS, GB/T and SAE standards.
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ISO 17804:2020(E)

5 Order information
The following information shall be supplied by the purchaser:
a) the complete designation of the material;
b) any special requirements (including the relevant wall thickness, when necessary)
All agreements shall be made between the manufacturer and the purchaser at the time of acceptance of
the order.
6 Manufacture
The method of producing ausferritic spheroidal graphite cast iron shall be left to the joint discretion of
the foundry and the heat treater.
The chemical composition shall be agreed upon between the manufacturer of the casting and the heat
treater.
The method of producing spheroidal graphite cast iron to be austempered shall be left to the discretion
of the foundry.
The heat treatment shall be left to the discretion of the heat treater.
Both shall ensure that the casting process and heat treatment process are carried out with the same
process parameters as the approved first sample(s).
7 Requirements
7.1 General
The property values of these materials apply to castings cast in sand moulds or moulds of comparable
thermal behaviour. Subject to amendments to be agreed upon in the order, they can apply to castings
obtained by alternative methods.
The material designation is based on the minimum mechanical properties obtained in separately cast,
cast side-by-side or cast-on samples with a thickness or diameter of 25 mm, cast in a sand mould or a
mould of comparable thermal behaviour, corresponding to a relevant wall thickness t ≤ 30 mm, as given
in Table 1.
For samples cut from the casting, the location shall be agreed between the manufacturer and the
purchaser.
The designation is irrespective of the type of cast sample.
Mechanical properties for test pieces cut from a casting are affected not only by material properties (a
subject of this document), but also by the local casting soundness (not a subject of this document).
Tensile, impact and any other mechanical testing requires sound material in the test pieces to provide
representative test results.
7.2 Test pieces machined from cast samples
7.2.1 General
The mechanical properties of ausferritic spheroidal graphite cast iron grades shall be as specified in
Table 1 and, if applicable, in accordance with the requirements given in 7.2.2.
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ISO 17804:2020(E)

Table 1 — Mechanical properties determined on test pieces machined from separately cast
[ ]
samples, side-by-side cast samples or cast-on samples 4
Relevant wall
Tensile 0,2 % proof Elongation after
Material designation thickness of
strength strength fracture
the casting
t R R A
m p0,2 5
MPa MPa %
mm
min. min. min.
t ≤ 30 800 10
ISO 17804/JS/800-10
30 < t ≤ 60 750 500 6
ISO 17804/JS/800-10RT
60 < t ≤ 100 720 5
t ≤ 30 900 8
ISO 17804/JS/900-8 30 < t ≤ 60 850 600 5
60 < t ≤ 100 820 4
t ≤ 30 1 050 6
ISO 17804/JS/1050-6 30 < t ≤ 60 1 000 700 4
60 < t ≤ 100 970 3
t ≤ 30 1 200 3
ISO 17804/JS/1200-3 30 < t ≤ 60 1 170 850 2
60 < t ≤ 100 1 140 1
t ≤ 30 1 400 1 100 1
ISO 17804/JS/1400-1 30 < t ≤ 60 1 170
To be agreed between the manufacturer
and the purchaser
60 < t ≤ 100 1 140
NOTE 1  The properties of castings are not uniform because of the complexity and variation in section thickness.
NOTE 2  With the appropriate heat treatment, the specified minimum 0,2 % proof strength values according to this
table can be maintained. However, with increasing casting wall thickness, the tensile strength and elongation values will
decrease.
2
NOTE 3  1 MPa = 1 N/mm .
7.2.2 Impact test
The impact energy values given in Table 2 at room temperature, if applicable, shall only be determined
if specified by the purchaser at the time of acceptance of the order.
Table 2 — Minimum impact energy values determined on V-notched test pieces machined from
[ ]
separately cast samples, side-by-side cast samples or cast-on samples 4
Relevant wall Minimum impact energy value at room
thickness of the casting temperature (23 ± 5 °C)
Material designation
Mean value of 3 tests Individual value
t
J J
mm
t ≤ 30 10 9
ISO 17804/JS/800-10RT 30 < t ≤ 60 9 8
60 < t ≤ 100 8 7
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ISO 17804:2020(E)

7.3 Test pieces machined from samples cut from a casting
If applicable, the manufacturer and the purchaser shall agree on:
— the location(s) on a casting where the sample(s) shall be taken;
— the mechanical properties that shall be determined;
— the minimum values (or allowable range of values) for these mechanical properties (for information,
see Annex E).
Tables 1 and 2 may be used for guidance on the likely mechanical properties of the castings. These
properties may be equal to or lower than those given in these tables.
7.4 Hardness
Guidance values for the Brinell hardness range of the material grades are given in Annex C.
The grades of abrasion-resistant ausferritic spheroidal graphite cast irons in terms of hardness shall be
as specified in Annex A.
7.5 Graphite structure
The graphite structure shall be predominantly of form Vl in accordance with ISO 945-1. A more precise
definition may be agreed upon at the time of the acceptance of the order.
This structure shall be confirmed by metallographic examination. The technique, visual or image
analysis, should be agreed upon at the time of the acceptance of the order.
Additional information regarding nodularity is given in Annex H.
7.6 Matrix structure
[1]
Information on matrix structure is given in ISO/TR 945-3:2016, Table 4.6 .
The matrix structure of the various grades of ausferritic spheroidal graphite cast iron consists
predominantly of ferrite and austenite, otherwise known as ausferrite. Other matrix constituents (e.g.
martensite, carbides) may be present at a level that will not affect the required mechanical properties.
Intercritical austenitization may be used to produce ISO 17804/JS/800-10 or 800-10/RT. This will
result in the formation of a mixed microstructure that includes the presence of proeutectoid ferrite.
Intercritical austenitization requires a higher hardenability than the grades specified in Table 1.
The cooling rate within some sections may not be sufficient to avoid the formation of pearlite or other
transformation products. In such cases, the maximum acceptable quantities of these microconstituents,
the locations within the casting and the mechanical properties in these locations may be agreed upon
between the manufacturer and the purchaser.
8 Sampling
8.1 General
Samples shall be provided to represent the castings produced.
Samples shall be made from the same material as that used to produce the castings which they
represent. The same melt and heat treatment processes shall be applied.
Several types of samples (separately cast samples, cast-on samples, side-by-side cast samples, samples
cut from a casting) can be used, depending on the mass and wall thickness of the casting (see Table 3).
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ISO 17804:2020(E)

When appropriate, the type of sample should be agreed between the manufacturer and the purchaser.
Unless otherwise agreed, the choice of the option is left to the discretion of the manufacturer.
When the mass of the casting exceeds 2 000 kg and its relevant wall thickness exceeds 60 mm, cast-
on samples or side-by-side cast samples should be preferably used. Representative dimensions and
the location of the sample shall be agreed between the manufacturer and the purchaser at the time of
acceptance of the order.
If the spheroidizing treatment is carried out in the mould (in-mould process), the separately cast sample
should be avoided.
All samples shall be adequately marked to guarantee full traceability to the castings which they
represent.
The samples shall be subject to the same heat tre
...